Foldable hinged prosthetic heart valve

ABSTRACT

Apparatus and methods are provided for use with a prosthetic valve that is designated for implantation at a patient&#39;s native heart valve, including a valve ring having a plurality of ring segments, each of the segments being hingedly coupled to an adjacent segment at a pivot joint. The valve ring is placed adjacent to a surface of the native heart valve, the prosthetic valve having been coupled to the valve ring. In an expanded state thereof, the valve ring defines a ring, all of the pivot joints being disposed in a plane that is perpendicular to a longitudinal axis of the ring. The valve ring is foldable into a shape that has a generally circular cross-section that defines and surrounds at least in part a central lumen, by folding the segments with respect to each other, at the pivot joints. Other embodiments are also described.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional patentapplication 61/283,819, entitled “Foldable hinged prosthetic heartvalve,” to Hacohen, filed Dec. 08, 2009, which is incorporated herein byreference.

FIELD OF EMBODIMENTS OF THE INVENTION

Embodiments of the present invention relates in general to valvereplacement. More specifically, embodiments of the present inventionrelates to replacement of an atrioventricular valve and prosthetic valvetherefor.

BACKGROUND

Ischemic heart disease causes regurgitation of a heart valve by thecombination of ischemic dysfunction of the papillary muscles, and thedilatation of the ventricle that is present in ischemic heart disease,with the subsequent displacement of the papillary muscles and thedilatation of the valve annulus.

Dilation of the annulus of the valve prevents the valve leaflets fromfully coapting when the valve is closed. Regurgitation of blood from theventricle into the atrium results in increased total stroke volume anddecreased cardiac output, and ultimate weakening of the ventriclesecondary to a volume overload and a pressure overload of the atrium.

SUMMARY OF EMBODIMENTS

In some applications of the present invention, a prosthetic heart valvestructure is provided that collapses and expands by means of one or morevalve pivot joints. The prosthetic valve structure is typicallydesignated for implantation in a native atrioventricular valve site of aheart of a patient, although for some applications, the prosthetic valvestructure is designated for implantation at the aortic or tricuspidvalve. The prosthetic valve structure comprises an annular ring portionthat is designated for placement adjacent to the ventricular surface ofthe native valve of the patient. This annular ring portion comprises thevalve pivot joints, which facilitate collapsing of the prosthetic valvestructure for transcatheter advancement of the valve toward the heart ofthe patient. Additionally, the annular portion of the prosthetic valvestructure is coupled to a plurality of anchors which are configured tograsp the native chordae tendineae of the heart of the patient. Theseanchors comprise generally curved prong structures which, in an expandedstate of the prosthetic valve structure, are aligned circumferentiallyalong the annular ring portion of the prosthetic valve structure(generally perpendicular to a radius of the annular ring portion). Oncethe annular ring portion is positioned adjacent to the ventricularsurface of the native mitral valve, the prosthetic valve structure isrotated, in order for the anchors to engage the native chordaetendineae. During the engaging, portions of the native chordae tendineaeare gathered between each anchor and a respective portion of the annularring. This engaging provides support to the prosthetic valve structureas it is positioned in and replaces the native valve. Additionally, theprosthetic valve structure comprises ventricular and atrial skirts whichprovide flush positioning of the prosthetic valve in the native valve.

There is therefore provided, in accordance with some applications of thepresent invention, apparatus for use with a prosthetic valve that isdesignated for implantation at a native heart valve of a patient,including:

a valve ring having a plurality of ring segments, each of the segmentsbeing hingedly coupled to at least one adjacent segment at a pivotjoint,

the valve ring being configured:

-   -   to be placed adjacent to a surface of the native heart valve,        the prosthetic valve having been coupled to the valve ring,    -   in an expanded state thereof, to define a ring, all of the pivot        joints being disposed in a plane that is perpendicular to a        longitudinal axis of the ring, and    -   to be foldable from the expanded state into a shape that has a        generally circular cross-section that defines and surrounds at        least in part a central lumen, by folding the segments with        respect to each other, at the pivot joints.

For some applications, the segments of the ring are configured to becomeat least partially twisted due to the ring being folded from theexpanded state.

For some applications, the prosthetic valve includes a trileaflet valve,and the ring has a number of ring segments that is a multiple of six.

For some applications, the ring has exactly six segments.

For some applications, the prosthetic valve includes a bileaflet valve,and the ring has a number of ring segments that is a multiple of four.

For some applications, the ring has exactly four segments.

There is further provided, in accordance with some applications of thepresent invention, a method for use with a prosthetic valve that isdesignated for implantation at a native heart valve of a patient,including:

placing in a vicinity a surface of the native heart valve, a valve ringthat is coupled to the valve, while the valve ring is in a folded statethereof,

-   -   the ring having a plurality of ring segments, each of the        segments being hingedly coupled to at least one adjacent segment        at a pivot joint,    -   in the folded state thereof, the ring having a shape that has a        generally circular cross-section that defines and surrounds at        least in part a central lumen;

expanding the ring such that all of the pivot joints become disposed ina plane that is perpendicular to a longitudinal axis of the ring, byapplying a force to at least some of the pivot joints; and

when the ring is in an expanded state thereof, positioning the ringadjacent to a surface of the native valve.

For some applications, applying the force to some of the pivot jointsincludes pushing on pivot joints that are disposed on a proximal side ofthe ring, while the ring is in the folded state thereof.

For some applications, the native valve includes a native mitral valve,and positioning the ring adjacent to the surface of the valve includespositioning the ring adjacent to a ventricular surface of the nativemitral valve.

There is additionally provided, in accordance with some applications ofthe present invention, apparatus for use with a prosthetic valve that isdesignated for implantation at a native mitral valve of a patient,including:

an annular ring configured to be placed at a ventricular surface of thenative mitral valve, the prosthetic valve having been coupled to theannular ring; and

at least one anchor disposed circumferentially with respect to theannular ring so as to define a space between the anchor and the annularring.

For some applications, the anchor is configured to grasp a portion ofnative chordae tendineae of a heart of the patient by the annular ringbeing rotated.

For some applications, the annular ring is configured to be collapsible.

For some applications, the ring includes a plurality of ring segments,each of the segments being hingedly coupled to at least one adjacentsegment at a pivot joint, and the ring is configured to be collapsed byfolding the segments with respect to each other, at the pivot joints.

There is further provided, in accordance with some applications of thepresent invention, a method, including:

positioning an annular ring portion of a prosthetic valve structure at aventricular surface of a native heart valve of a patient; and

grasping a portion of native chordae tendineae of a heart of the patientby rotating the annular ring portion of the prosthetic valve structure.

In some applications of the present invention, grasping the portion ofthe native chordae tendineae includes facilitating placing the portionof the native chordae tendineae in a space between a segment of theannular ring portion and an anchor disposed circumferentially withrespect to the segment of the annular ring portion.

In some applications of the present invention, positioning the annularring portion includes:

transcatheterally advancing the prosthetic valve structure toward thenative valve of the patient in a collapsed state thereof; and

expanding the prosthetic valve structure from the collapsed state.

In some applications of the present invention, expanding the prostheticvalve structure includes pivoting a plurality of segments of the annularring portion at respective pivot joints that couple together adjacentsegments of the annular ring portion.

The present invention will be more fully understood from the followingdetailed description of embodiments thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exploded view of a prostheticheart valve, in accordance with some applications of the presentinvention;

FIGS. 2A-B are schematic illustrations of the prosthetic heart valve ofFig. I in an assembled, collapsed state, in accordance with someapplications of the present invention;

FIG. 3 is a schematic illustration of the prosthetic heart valve of FIG.1 in an assembled, expanded state, in accordance with some applicationsof the present invention; and

FIG. 4 is a schematic illustration of respective views of the prostheticheart valve of FIG. 1, while anchors of the valve are anchoring thevalve to chordae tendineae of a subject, in accordance with someapplications of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference is now made to FIGS. 1-4, which are schematic illustrations ofan expandable and collapsible prosthetic valve structure 20, inaccordance with some applications of the present invention. Theprosthetic valve structure is configured for implantation in andreplacement of a native atrioventricular valve of a patient. Typically,the prosthetic valve structure is configured for implantation in andreplacement of a native mitral valve of the patient.

The prosthetic valve structure comprises an annular valve ring 24, whichcomprises a plurality of curved metal segments 26 and a plurality ofpivot joints 30 which facilitate the collapsing and expanding of theprosthetic valve structure. The annular valve ring is typicallysurrounded by a valve ring fabric sleeve 34 comprising a braided mesh offabric, e.g., Dacron. This sleeve promotes fibrosis followingimplantation of the prosthetic valve structure in the native valve ofthe patient. The annular valve ring is coupled to a prosthetic valvethat includes a plurality of valve leaflets 44. The valve leaflets arecoupled to a flexible valve leaflet frame 40 (e.g., comprising nitinol,by way of illustration and not limitation), which is, in turn, coupledto a valve leaflet frame fabric 42. Typically, the valve leaflet framefabric (e.g., a fabric comprising Dacron) is coupled to (for example,sutured to) valve ring fabric sleeve 34.

For embodiments in which the prosthetic valve is designated to replacethe native mitral valve of the patient, the prosthetic valve comprisesthree artificial or tissue-based leaflets 44 a, 44 b, and 44 c (shown inFIG. 4), which are coupled to the inner perimeter of the annular valvering. For example, the leaflets may include pericardium, a polymer,and/or other materials, as would be obvious to one skilled in the art.

The annular valve ring portion of the prosthetic valve structure iscoupled: (1) at a first surface thereof to an upper skirt, whichcomprises an upper skirt fabric 38 coupled to a flexible upper skirtframe 36, and (2) at a second surface thereof to a lower skirt, whichcomprises a lower skirt fabric 48 coupled to a flexible lower skirtframe 46. Typically, the upper and lower frames comprise a flexiblematerial, e.g., nitinol by way of illustration and not limitation.Typically, when the prosthetic valve structure is implanted in theexpanded state, as shown in FIG. 4:

(a) the annular valve ring portion is configured to be disposed at aventricular surface of the native valve,

(b) the upper skirt is designated to rest against an atrial portion ofthe native mitral valve, and

(c) the lower skirt is designated to rest against a ventricular surfaceof the native valve and to push radially the native leaflets of thenative valve.

FIG. 1 shows components 22 of valve structure 20 in an exploded view.Each segment 26 of annular valve ring 24 is coupled at its respectiveends to respective ends of adjacent segments via a hinge. For example,as shown, the hinge may include a connecting element 28 that is insertedinto holes in the ends of the adjacent segments, such that the adjacentsegments form a pivot joint 30. The pivot joints of the ring portionenable the entire prosthetic valve structure to pivot into a collapsedstate, the collapsed state being shown in FIGS. 2A-B. Typically, thevalve comprises: (a) three “upper” valve pivot joints 30U (shown in FIG.2A) which are disposed at 120 degrees along the annular valve ring andare near the upper skirt frame 36, in the collapsed state of the valve,shown in FIG. 2A; and (b) three “lower” valve pivot joints 30L (shown inFIG. 2A) also disposed with a separation therebetween of 120 degrees,alternating with the upper valve pivot joints. The lower valve pivotjoints are near the lower skirt frame 46, in the collapsed state of thevalve as shown in FIG. 2A. The upper valve pivot joints are exposed at aproximal portion of the valve in the collapsed state of the valve (i.e.,adjacent to an upper skirt region of the prosthetic valve structure, asshown in FIG. 2A), such that a physician is able to push on the uppervalve pivot joints with a pushing tool, as described hereinbelow.Typically, when the ring is in its expanded state, all of the pivotjoints are disposed in a plane that is perpendicular to longitudinalaxis 10 of ring 24.

The pivot joints enable the prosthetic valve structure to collapse toform a shape having a generally circular cross-section that defines andsurrounds at least in part a central lumen 50, as shown in FIGS. 2A-B.Typically, the pivot joints enable the valve to assume an outer diameterof less than 10 mm, e.g., less than 6 mm (by way of illustration and notlimitation), in its collapsed state, as shown in FIG. 2A. Furthertypically, central lumen 50 (which is defined by ring 24 in itscollapsed state) has a cross-sectional length (e.g., diameter D, shownin FIG. 2B) of between 3 mm and 5 mm, the length being measured in aplane that is perpendicular to longitudinal axis 10 of the valve (shownin FIG. 1).

Typically, when used with a trileaflet valve, ring 24 includes sixsegments 26, such that there are a total of six pivot joints 30 (ofwhich three are upper pivot joints 30U, and three are lower pivot joints30L), and such that each of the leaflets is disposed between twoadjacent upper pivot joints 30U, or two adjacent lower pivot joints 30L.For some applications, the ring includes twelve (or another multiple ofsix) pivot joints, such that each of the leaflets of a trileaflet valveis disposed between two non-adjacent upper pivot joints 30U, or twonon-adjacent lower pivot joints 30L. For some applications, ring 24 isused with a bileaflet valve. For such applications, the ring may includefour, eight, or twelve segments 26, such that there are a correspondingnumber of pivot joints, and such that each of the leaflets is disposedbetween two of the upper pivot joints or two of the lower pivot joints.

Each of segments 26 of ring 24 is configured to become twisted when thering is folded, as shown in FIG. 2A. For some applications, due toshape-memory properties of the segments, the segments facilitate theexpansion of the ring, since the segments are pre-shaped in non-twistedshapes.

In the collapsed state of the valve, the valve leaflet frame, the valveleaflets, the upper skirt, and the lower skirt are also collapsed.Typically, the valve is configured such that the expansion of the ringcauses each of the aforementioned portions to become expandedautomatically.

In order to deploy prosthetic valve structure 20 inside the heart, thephysician pushes the upper pivot joints 30U distally, using a pushingtool. The pushing of the upper pivot joints enables annular valve ring24 to expand radially in order for the prosthetic valve structure toassume an expanded state, as shown in FIG. 3. Responsively to theexpanding of the prosthetic valve structure, valve leaflet frame 40,valve leaflets 44, upper skirt frame 36, and lower skirt frame 46 alsoexpand from their respective collapsed states.

For some applications, annular valve ring 24 is coupled to a pluralityof generally curved, prong-shaped anchors 32, for example, four to eightanchors, e.g., six anchors, as shown by way of illustration and notlimitation in FIG. 1. In the expanded state of valve structure 20, asshown in FIG. 3, the anchors are disposed circumferentially and inconcentric alignment with the annular valve ring. As shown in FIG. 3,the anchors project from the annular valve ring through the valve ringfabric sleeve 34. As the prosthetic valve structure transitions to acollapsed state, as shown in FIG. 2A, the anchors remain alongsiderespective segments of the annular valve ring to which each anchor isadjacently disposed in the expanded state of the prosthetic valvestructure.

During implantation of prosthetic valve structure 20, a lower portion ofthe prosthetic valve structure is first advanced toward the ventricularsurface of the native valve. Once the distal end of the catheter ispositioned in the ventricle of the patient, the physician pushesdistally on the upper valve pivot joints 30 in order to (1) exposeannular valve ring portion 24 and the lower skirt frame 46 and lowerskirt fabric 48 from within the catheter, and (2) in conjunction, expandthe annular valve ring. As the annular valve ring expands, lower skirtframe 46, valve leaflet frame 40, and valve leaflets 44 passively (i.e.,automatically) expand. As the physician expands the annular valve ring,each of the anchors remain disposed circumferentially with respect tothe segment of the annular valve ring to which the anchor is adjacentlydisposed (as shown in FIG. 3). In such a manner, a space is createdbetween each anchor and the respective segments of the annular valvering to which each anchor is adjacently disposed.

By pulling proximally on the catheter and the tool coupled to prostheticvalve structure 20 disposed therein, the annular valve ring ispositioned adjacent to a ventricular surface of the native valve. Oncethe valve ring portion is positioned adjacent to the ventricularsurface, the physician rotates annular valve ring 24 (e.g., by rotating30 degrees a tool coupled thereto) about an axis that runs between thenative valve from the atrium to the ventricle (which during implantationof the valve, is typically approximately aligned with longitudinal axis10 of the valve). During this rotation, portions of native chordaetendineae 60 are grasped and placed between each anchor and therespective segment of the annular valve ring to which the anchor isadjacently disposed, as shown in FIG. 4. This grasping of the leafletsprovides supplemental support to the prosthetic valve during andfollowing implantation thereof. Alternatively or additionally, supportis provided to the prosthetic valve by the upper and lower skirts,and/or by ring 24.

In conjunction with the grasping of the chordae tendineae, theprosthetic valve is secured in place. The physician then pulls thecatheter proximally in order to expose upper skirt frame 36 and upperskirt fabric 38 from within the catheter. The skirt then expands overthe atrial surface of the native valve in order to create a flushcoupling between the prosthetic valve and the native valve.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1. Apparatus for use with a prosthetic valve that is designated forimplantation at a native heart valve of a patient, comprising: a valvering having a plurality of ring segments, each of the segments beinghingedly coupled to at least one adjacent segment at a pivot joint, thevalve ring being configured: to be placed adjacent to a surface of thenative heart valve, the prosthetic valve having been coupled to thevalve ring, in an expanded state thereof, to define a ring, all of thepivot joints being disposed in a plane that is perpendicular to alongitudinal axis of the ring, and to be foldable from the expandedstate into a shape that has a generally circular cross-section thatdefines and surrounds at least in part a central lumen, by folding thesegments with respect to each other, at the pivot joints.
 2. Theapparatus according to claim 1, wherein the segments of the ring areconfigured to become at least partially twisted due to the ring beingfolded from the expanded state.
 3. The apparatus according to claim 1,wherein the prosthetic valve includes a trileaflet valve, and whereinthe ring has a number of ring segments that is a multiple of six.
 4. Theapparatus according to claim 3, wherein the ring has exactly sixsegments.
 5. The apparatus according to claim 1, wherein the prostheticvalve includes a bileaflet valve, and wherein the ring has a number ofring segments that is a multiple of four.
 6. The apparatus according toclaim 5, wherein the ring has exactly four segments.
 7. A method for usewith a prosthetic valve that is designated for implantation at a nativeheart valve of a patient, comprising: placing in a vicinity a surface ofthe native heart valve, a valve ring that is coupled to the valve, whilethe valve ring is in a folded state thereof, the ring having a pluralityof ring segments, each of the segments being hingedly coupled to atleast one adjacent segment at a pivot joint, in the folded statethereof, the ring having a shape that has a generally circularcross-section that defines and surrounds at least in part a centrallumen; expanding the ring such that all of the pivot joints becomedisposed in a plane that is perpendicular to a longitudinal axis of thering, by applying a force to at least some of the pivot joints; and whenthe ring is in an expanded state thereof, positioning the ring adjacentto a surface of the native valve.
 8. The method according to claim 7,wherein applying the force to some of the pivot joints comprises pushingon pivot joints that are disposed on a proximal side of the ring, whilethe ring is in the folded state thereof.
 9. The method according toclaim 7, wherein the native valve includes a native mitral valve, andwherein positioning the ring adjacent to the surface of the valvecomprises positioning the ring adjacent to a ventricular surface of thenative mitral valve.
 10. Apparatus for use with a prosthetic valve thatis designated for implantation at a native mitral valve of a patient,comprising: an annular ring configured to be placed at a ventricularsurface of the native mitral valve, the prosthetic valve having beencoupled to the annular ring; and at least one anchor disposedcircumferentially with respect to the annular ring so as to define aspace between the anchor and the annular ring.
 11. The apparatusaccording to claim 10, wherein the anchor is configured to grasp aportion of native chordae tendineae of a heart of the patient by theannular ring being rotated.
 12. The apparatus according to claim 10,wherein the annular ring is configured to be collapsible.
 13. Theapparatus according to claim 12, wherein the ring comprises a pluralityof ring segments, each of the segments being hingedly coupled to atleast one adjacent segment at a pivot joint, and wherein the ring isconfigured to be collapsed by folding the segments with respect to eachother, at the pivot joints.
 14. A method, comprising: positioning anannular ring portion of a prosthetic valve structure at a ventricularsurface of a native heart valve of a patient; and grasping a portion ofnative chordae tendineae of a heart of the patient by rotating theannular ring portion of the prosthetic valve structure.
 15. The methodaccording to claim 14, wherein grasping the portion of the nativechordae tendineae comprises facilitating placing the portion of thenative chordae tendineae in a space between a segment of the annularring portion and an anchor disposed circumferentially with respect tothe segment of the annular ring portion.
 16. The method according toclaim 14, wherein positioning the annular ring portion comprises:transcatheterally advancing the prosthetic valve structure toward thenative valve of the patient in a collapsed state thereof; and expandingthe prosthetic valve structure from the collapsed state.
 17. The methodaccording to claim 16, wherein expanding the prosthetic valve structurecomprises pivoting a plurality of segments of the annular ring portionat respective pivot joints that couple together adjacent segments of theannular ring portion by distally pushing one or more of the pivot jointsin a manner in which the ring portion expands radially.